Piano action



Patented Apr. 15, 1947 PIANO ACTION Francis 0. Socin, St. Charles, 111.,assignor to The Rudolph Wurlitzer Company, Chicago, 111., a

corporation Application July 21, 1944, Serial No. 545,902

(Cl. S4-240) 2 Claims.

This invention relates to a piano action, particularly relating to thehammer actuating jack and associated elements.

In the usual piano action the free end of the jack loosely abuts thehammer butt for forwardly impelling the hammer. Following this action,however, the free end of the jack slides to the rear of the butt andthereupon becomes ineffectual for actuating the hammer until it returnsto initial position upon the key being released. By reason thereof suchpiano actions do not have the double repetition action available ingrand pianos, wherein the hammer is operable through intermediate ilngeractions on the key. It is, therefore, the purpose of thisinvention toprovide a flexing jack which is tied permanently in flexing engagementwith the hammer butt so as to be at all times effective in actuating thehammer during intermediate positions of the key, resulting in thedesired greater repetition action. This is accomplished by pivotallyconnecting the free end of the jack with the hammer butt through a linkoperable in the manner to be hereinafter more particularly described.

A further feature and advantage of the invention resulting from thelinked connection between the jackand the butt resides in an actionwherein the usual bridle tape and bridle wire are eliminated, the designof the butt and means for obtaining escapement of the hammer from thestring being substantially changed from that usually employed. Thepivotally linked jack provides escapement of the hammer from the tringwhen the contact button is engaged-by the jack making it unnecessary toprovide the usual butt knuckle and bridle tape such as to providegreater repetition in the action. Thus, the usual jack spring willreturn the linked jack to effective position upon partial release of thepiano key after strikmg.

A further feature of the invention resides in an adjustable back checkwhich may be attached directly to the butt for checking the backwardthrow of the hammer and prevent any secondary rebound of the hammertoward the string.

It may also be noted that by reason of this improvement the action willnot be blocked either by the packing of the front rail key punching, orby compression of the back check cushion as occurs in the usual action.It also has the effect of eliminating the friction of the jack on thebutt knuckle, and the necessity of regulating the back check and bridletape.

The full nature of the invention will be understood from theaccompanying drawing and the following description and claims:

Fig. 1 is a sectional view through a piano action showing a unit thereofwith a portion of itsa'ssociated actuating piano key in normal position.

Fig. 2 is thesame as Fig. 1 showing the action in key actuated position.

Fig. 3 is anenlarged section of the slip joint bushing of the jack.

Fig. 4 shows a modified form of back check.

Fig. 5 shows a modified form of removable connection between the jackand wippen.

In the-drawing there is showna unit of a piano action including anaction rail it), frame structure ii, and upper rail i2, all associatedand arranged in the usual manner with respect to the piano strings 53mounted on the back plate M.

The action herein shown by way of illustration is of the charactergenerally employed in upright pianos, and embodies a hammer l5associated with a string damper l5 and wippen [1. The wippen isfulcrumed at l8 on the rail III by a supporting flange Ili Associatedwith the wippen there is-provided a. piano key is supported for actionupon the keyboard 28. The actuating end of said key is provided with theusual capstan screw 2! engaging a cushionin felt 2| on the Wipp n lSecured to the wippen and upstanding therefrom is a jack supportinflange 22 which is bifurcated and provided with a pivot pin 3| forremovably receiving and pivotally supporting the jack.

The jack, instead of being a rigid stick, is knuckled for flexibilityand comprises a jack member 23 having its upper end pivotally connectedat 24 to a link 25, the other end of which is pivotally connected at 25to the underside of the hammer butt 2?. ihe jack is provided with a heelportion 28 engageable with the adjustable contact button 29 uponactuation of the piano key. As shown in Fig. 3, the lower end of thejack is adapted to slip between the bifurcated portion of the flange 22and i provided with a slip joint bushing 30 having a facing thereonarranged to spring over the pivot pin 3| carried by the flange. Thus thejack may be readily slipped on and off of the wippen. In the usualmanner, between the heel 28 on the jack and the wippen there is acompression spring 32.

Extending rearwardly and downwardly from the hammer butt there isprovided a wire back check 33 positioned for engagement by a leathercovered cushion 34 secured to the adjacent surface of the jack. The backcheck 33 may be preferably made of wire with one end secured in thehammer butt, the other end curved and flattened at 33 for engagement bythe cushion. Thus the back check is adjustable by bending to adjust theescapement. In the modified form shown in Fig. 4 the wire back check I33is similarly mounted upon the butt 21, its free end terminating in awooden head I35 carrying the cushion 134 thereon for direct engagementby the wippen.

In operation it is to be noted that the flexible link jack is at alltimes during actuation of the piano key permanently connected to thehammer butt as well as to the wippen. Therefore, at no time does thebutt end of the jack slide ofi to one side of the butt knuckle toprovide escapement of the hammer from the string as in the standardpractice. It is, therefore, not necessary for the key to be completelyreleased to permit the jack to move back into actuating position, sinceits pivotal connection 25 remains permanently in fixed position.However, by reason of its flexibility due ot the link 25 it permits ofthe required escapement of the hammer from the string. Upon the keybeing partially released after striking, instead of fully released asheretofore, the jack spring flexes or pivots the jack back to normalstriking position sufliciently to permit the key to strike a subsequentblow Without the key returning to the normal at rest position. Thus thejack need not return to its overcenter position from that shown in Fig.2 to that of Fig. l in order to actuate the hammer. It need onlyapproach its straightened out position which it will do upon the keybeing partially released. 111 such position as indicated by the dottedline in Fig. 2 and with the key only partially released, furtheractuation of the key will impress the necessary force on the hammer tostrike the string through the jack. In this manner and by reason of theflexibl jack anchored at one end to the hammer butt, double repetitionas in a grand piano action is made possible.

This construction also permits of convenient adjustment by reason of therelation of the wire back check to the butt and flexible jack. It willbe noted that the back check may be slightly bent for obtaining properadjustment to thereby avoid the usual regulation as well as permitelimination of the bridle tape and bridle tape wire. Wherein theflexibility of the jack is attained as shown herein by the pivotal linkarrangement and with its permanent connection to the hammer butt, theusual sliding friction therewith is avoided, the usual butt knuckleeliminated and blocking thereof either by packing of the front rail keypunching or by compression of the back check cushion is avoided.

It may be further noted that inasmuch as the jack is more or lesspermanently connected to the butt as distinguished from the usualsliding engagement therewith, it is of advantage to removably connect itat its lower end to the wippen as indicated in Fig. 3. Thus the slipjoint bushing 30 may be readily slipped on and off of the pivot 3| onthe wippen flange 22, while at the same time being pivotally retainedthereon under tension exerted on the bifurcated portion by the clampingscrew 35,

In the modified form of Fig. 5, the flange I22 which pivotally connectsthe jack 23 to the wippen H1, is removably secured to the wippen by thescrew I24. Thus in this modification the jack is permanently pivoted tothe flange, but still is removable from the wippen.

The invention claimed is:

1. In a piano having actuating keys, a hammer action mounted to strike apiano string including a hammer butt, a wippen operable by one of saidkeys, a jack connected at each end to said wippen and hammer buttrespectively, said jack being flexed upon actuation by said key toprovide escapement of the hammer from said string, and a back checkhaving a bendable support secured to said butt extending downwardly intoposition to be engaged by said jack for limiting its flexing movement,said support being bendable to effect adjustment thereof.

2. In a piano having actuating keys, a hammer action mounted to strike apiano string including a hammer butt, a wippen mounted below said buttoperable by one of said keys, and a. jack pivotally mounted on saidwippen having a link connection with said butt pivoted thereto, saidlink connection permitting said jack to be flexed upon actuation by saidkey to provide escapement of the hammer from said string, and a wireback check secured to said butt and bendable into adjusted position forengagement by said jack to limit its movement and permit escapementadjustment of the hammer.

FRANCIS C. SOCIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 326,576 Menges Sept. 22, 18852,260,310 Gould Oct. 28, 1941 172,621 Frickinger Jan. 25, 1876 472,109Dimick Apr, 5, 1892 1,090,192 Blessing Mar. 17, 1914

